Lanamar de Almeida Carlos

Influência dos estádios de maturação na qualidade do suco do maracujá-amarelo

This work evaluated the influence of the ripening stages on the chemical characteristics of the yellow passion fruit juice (Passiflora edulis f. flavicarpa Degener.), during the period that precedes the peel color change until the period of fruits abscission, when they show the peel totally yellowish. During the ripening of the fruits was observed a progressive increase in the Hunter L and b parameter, in a way that the lower area of the fruit presented higher brightness and yellowing indexes than the upper area. The content of SST showed a progressive increase from an immature condition of the fruits (52 DAA) until a ripening stage with 65% of yellowish peel, in 76 DAA, staying constant after this period. The measures of total acidity and pH indicated a small accumulation of organic acids in the immature fruits (60 DAA) and, later, it occurred a partial consumption of these acids, as showed by the decreasing of titrable acidity and the increasing of pH during the ripening of the yellow passion fruit. The TSS/TA ratio also increased progressively in this period.

Qualidade do suco de maracujá-amarelo em diferentes épocas de colheita

Yellow passion fruit presents seasonal production and occurs in the winter and summer harvest seasons. The aim of this work was to evaluate the influence of two different harvest seasons on the quality of yellow passion fruit (Passiflora edulis f. flavicarpa Degener) juice, in seven maturation stages. The experiments were constituted of two harvest seasons (EP 1 and EP 2) and seven maturation stages, with 10 repetitions. The results were evaluated through the Tukey test at a 5% probability level. In EP 1, characterized by lower temperatures and lower total precipitation, the fruits presented higher Total Titratable Acidity (TTA), total soluble solids content (TSS), dry matter and TSS/TTA ratio, and lower pH, until the ripening stage of 65% yellow color of the peel, when compared with EP 2. After this stage no difference in TSS content between harvest seasons was found. However, the juice of totally mature fruits presented lower contents of dry matter and TSS/TTA ratio in the EP 1 season, as well as higher acidity. It was concluded that yellow passion fruit can be harvested with 65% yellow color of the peel in harvest season EP 1, due to the maintenance of chemical quality; however, in harvest season EP 2, the fruits showed an increase in the TSS/TTA ratio until the mature stage.

Determinação da escala de coloração da casca e do rendimento em suco do maracujá-amarelo em diferentes épocas de colheita

This work had the aim to determinate the peel color scale intended to identify the ripening stage of the yellow passion fruit and evaluate its juice yield in different harvest seasons. The experiments were constituted of 2 harvest seasons and they were accomplished during the period of low temperatures and less precipitation (EP1 - May/September) and high temperatures and more precipitation (EP2 - October/December), and seven ripening stages using ten replications. The results were compared by applying the Tukey test at the level of 5% of probability. Hunter b parameter was used as the yellowing index. It was verified that the yellow color progressed from the base to the fruit peduncle. Fruits from the EP2 season presented the lowest juice yield and the highest peel thickness in the early ripening stages. In fruits with at least 65% of yellow color peel, the harvest season did not influence in the peel thickness and in the juice yield, showing the highest level of juice. Fruits from the EP1 season showed the higher juice yield after 21,3% yellow color.

Effect of the storage time and temperature on phenolic compounds of sorghum grain and flour.

This study evaluated the effect of storage temperature (4, 25 and 40°C) and time on the color and contents of 3-deoxyanthocyanins, total anthocyanins, total phenols and tannins of sorghum stored for 180days. Two genotypes SC319 (grain and flour) and TX430 (bran and flour) were analyzed. The SC319 flour showed luteolinidin and apigeninidin contents higher than the grain and the TX430 bran had the levels of all compounds higher than the flour. The storage temperature did not affect most of the analyzed variables. The content of most of the compounds reduced during the first 60days when they became stable. At day 180, the retention of the compounds in the genotypes SC319 and TX430 ranged from 56.1-77.9% and 67.3-80.1% (3-deoxyanthocyanins), 88.4-93.8% and 84.6-96.8% (total anthocyanins) and 86.7-86.8 and 89.4-100% (phenols) respectively. The retention of tannins ranged from 56.6 to 85.3%. The color of samples remained stable for 120days.

Influência dos estádios de maturação sobre as características físicas dos frutos de maracujá-amarelo

The objective of this work is to evaluate the influence of maturation stage on physical characteristics of yellow passion fruits, in order to indicate the best moment for harvesting in the Fluminense North area. The samplings were accomplished in 52 days after anthesis (DAA), before the first changes of color of the peel has been observed, following in intervals of 54, 56, 58, 60, 64, 66, 68, 70, 76, 83 and 100 DAA. In the last harvest day the marked fruits had suffered abscission during the night. During fruits ripening occurred a progressive increase of Hunter L and b parameters where the inferior area of the fruit presented higher brightness and yellowing index than the superior. The fruits reduced the thickness of the peel until the moment of the color change (64 DAA), with inversely proportional increase of juice yield in this period, taking values higher than 33% which is appropriate for industrialization. It was observed a trend of increase in juice yield to 40% in the fruits with approximately 30% of yellow color peel (68 DAA).

Rauvolfia grandiflora (Apocynaceae) extract interferes with staphylococcal density, enterotoxin production and antimicrobial activity

Staphylococci bacteria are involved in many human and animal infections and development of alternative antimicrobial drugs against pathogenic bacteria is of great interest to the pharmaceutical industry. This study investigated the in vitro effect of Rauvolfia grandiflora methanol extract (root bark fraction) (RGE) on the density of ATCC strains of Staphylococcus aureus and Staphylococcus epidermidis, and a clinical enterotoxin-producer, S. aureus bovine strain. The alkaloid, isoreserpiline, obtained from dichloromethane extract of R. grandiflora was ineffective against the strains tested. After incubation of staphylococci strains in the presence of 1.2 μg.mL-1 RGE, a significant inhibition of cell growth was observed using both spectrophotometry and ELISA assays. Twelve drugs were evaluated for their antimicrobial effects on culture RGE-treated cells using the disk diffusion method. Penicillin resistant strains became sensitive to the drug after RGE treatment. Furthermore, enterotoxin production by RGE-treated S. aureus was evaluated using a standardized ELISA method. Although staphylococcal LSA 88 bovine strain cells remained viable after exposure to the extract, enterotoxin production was precluded in 20% after RGE treatment. Significant interference in staphylococci cell density, drug sensitivity and enterotoxin secretion was observed after treatment. The study highlights the necessity to find new methods of disease prevention and new antibiotic therapies against staphylococcal infections.

Non-destructive prediction of pigment content in lettuce based on visible-NIR spectroscopy.

BACKGROUND Lettuce (Lactuca sativa L.) is one of the most important salad vegetables in the world, with a number of head shapes, leaf types and colors. The lettuce pigments play important physiological functions, such as photosynthetic processes and light stress defense, but they also benefit human health because of their antioxidant action and anticarcinogenic properties. In this study three lettuce cultivars were grown under different farming systems, and partial least squares models were built to predict the leaf chlorophyll, carotenoid and anthocyanin content. RESULTS The three proposed models resulted in high coefficients of determination and variable importance for the projection values, as well as low estimative errors for calibration and external validation datasets. These results confirmed that it is possible to accurately predict chlorophyll, carotenoid and anthocyanin content of green and red lettuces, grown in different farming systems, based on the spectral reflectance from 500 to 1000 nm. CONCLUSION The proposed models were adequate for estimating lettuce pigments in a quick and non-destructive way, representing an alternative to conventional measurement methods. Prediction accuracies were improved by using the detrending, smoothing and first derivative pretreatments to the original spectral signatures prior to estimating lettuce chlorophyll, carotenoid and anthocyanin content, respectively.

Characterization of two types of azedinha in the region of Sete Lagoas, Brazil

Azedinha (Rumex acetosa) is a vegetable crop species consumed in natura in salads and pertains to the group of non-conventional vegetables. These rustic plants are often considered weeds plants. There exist two types of native azedinha in the Sete Lagoas region, Minas Gerais state, Brazil, that are usually grown in family gardens and here denominated Type I and Type II. In this study we characterized the morphologic, physic-chemical and chromatic characteristic of these two types of azedinha. The study was carried out in randomized complete blocks with four replications in dependences of the EPAMIG (Non-Conventional Vegetable Bank) in Prudente de Morais, Brazil. Plants were trained to the point of harvest, 90 days after the planting of seedlings, when they were harvested for analysis. We evaluated the characteristics on the leaves: weight, length, width, number of veins, width/length ratio, transverse and longitudinal diameter of the base of the petiole and longitudinal and transverse diameter ratio of the base of the petiole. We also evaluated the contents of macro and micronutrients and chemical characteristics of the plant. There are significant differences between the assessed characteristics between azedinha types I and II. We concluded that the plants probably belong to two different varieties.

NOVEL ALKALOID FROM Rauvolfia capixabae (APOCYNACEAE)

A new sarpagine-type alkaloid, Na-methylrauflorine (1), was isolated from Rauvolfia capixabaetogether with isoreserpiline (2),Nb-oxide-isoreserpiline (3), ajmalicine (4), perakine (5) and vinorine (6) alkaloids. These compounds were characterized based on their spectral data basis, mainly one- (1H, 13C, APT) and two-dimensional(1H-1H-COSY, 1H-1H-NOESY, HMQC and HMBC) NMR, and mass spectra, also involving comparison with data from the literature.

ATIVIDADE ANTIMICROBIANA DE EXTRATOS VEGETAIS FRENTE À BACTÉRIAS DE IMPORTÂNCIA MÉDICA

O uso indiscriminado de antimicrobianos determina um processo de selecao de micro-organismos patogenicos que apresentam resistencia a maioria dos compostos quimicos utilizados na agropecuaria e na medicina. Uma alternativa eficaz e economica tem sido o desenvolvimento e o uso de produtos naturais com propriedades antimicrobianas. Este trabalho teve como objetivo avaliar a atividade antimicrobiana de extratos de Punica granatum, Anacardium occidentale e Psidium guajava frente a cepas de Stafhylococcus aureus, Stafhylococcus epidermidis, Escherichia coli e Pseudomonas aeruginosa. A investigacao foi conduzida utilizando o metodo de difusao em agar e inoculo bacteriano padronizado, com pocos perfurados no agar, nos quais foram adicionados volumes conhecidos das substâncias testadas: gentamicina (controle positivo), DMSO (controle negativo) e extratos vegetais. As placas foram incubadas a 37 oC por 24 horas e mensurado o diâmetro dos halos de inibicao. Os extratos diclorometânico e metanolico das cascas de Punica granatum e metanolicos das folhas de Anacardium occidentale e Psidium guajava, na concentracao de 1 g/ml, foram mais efetivos contra as cepas de S. aureus, S. epidermidis, E.coli. Posteriormente, esses extratos foram utilizados para o teste de sinergismo em associacao a antibioticos padronizados, no qual foi observado efeito sinergico frente as bacterias testadas, com excecao da P. aeruginosa. Palavras-Chave: Extratos fitoquimicos. Agentes antibacterianos. Sinergismo farmacologico.